For each weather station, you will see a temperature along with tables of data organized into percentage columns. The percentage column tells you the probability that you will experience that row's temperature on or near that date. Here are two examples to help you determine your probable last frost and first freeze dates.

Example 1 (Last Frost). In the Spring 32° row, if you have "Apr 15" under the 50% column, that means you have a 50% chance of seeing frost on or before April 15th.

Example 2 (First Freeze). In the Fall 24° row, if you have "Dec 1" under the 90% column, that means you have a 90% chance of seeing 24 degrees on or after December 1st.

Empty cells indicate you have a less than 10% chance of ever seeing that temperature.